Wire feed gear train lubrication



April 15, 1952 A. P. $H'EPARD WIRE FEELS GEAR ThAIN LUBRICK'TION I s Sheets-Sheet 1 Filed Oct. 5, 1946 fnruenfor AR HUR BSH-EPARD y a April 15, 1952 EPA 2,592,607

WIRE FEED GEAR TRAIN LuR'IcATIoN'" rnwout. 5, ;945 I 5 Shaegts-heet 2 -Har JIM/@1 07 ARTHUR R SHEPARD Ap 15, 1952 A. P. SHEPARD 2,592,607

f WIRE FEED GEAR TRAINTLUBRICAIION r Fil ed Oct. 5, 1946 s Sheets-Sheet 5 [mm ARTHUR I? SHEPARD April 15, 1952 7' I A; P. 8 2,592,607 '1 WIRE FEED GEAR TRAIN LUBRICATION Filed not, 5', 1946 5 Sheet-Sheet 4 9 6 Zmmztar ARTHUR H SH ARD 7 46/1 $05M?) A. P. SHEPARD WIRE FEED GEAR TRAIN LUBRICATI'ON April 15, 1952 5 Sheets-Sheet 5 Filed Oct. 5, 1946 [WI/022%? ARTHUR P'SHEPARD Patented Apr. 15, 1952 WIRE FEED GEAR TRAIN. LUBRICATION.

Arthur P. Shepard, Flushing, N. Y., assignor to Metallizing Engineering Co. 1110., Long Island City; N. Y., a corporation of New Jersey Application October 5, 1946, .SerialNo. 701,586 6 Claims. (01.184-11) This invention relates to new and useful improvements in wire feed gear train lubrication.

Heat. fusible material spray guns of the wire feed type are devices in which such material is continuously fed in wire form into a melting zonein which it is melted, being thereafter expelledfrom the gun in subdivided form by a blast of air or other gas. Amixture of fuel gas and combustion supporting gas, such as a mixture of acetylene or propane and air or oxygen, is fed to the melting zone through suitable jets, which discharge the combustible gas mixture, which when ignited causes the melting of the material.

The construction of heat fusible material spray guns of the wire feed type usually includes a source of power for feeding the wire. be any motive power but is conventionally a compressed gas turbine such as air turbine. The construction of such guns also conventionally includes a gear train incorporating reduction gearing to provide the necessary speed for the wire feeding mechanism. Because of the nature of the use of these type spray guns they are necessarily restricted in size and the gears, and gear cases, are necessarily relatively small. Furthermore, these guns in practical operation, frequently require to be mounted in various positions other than horizontal. Thus, it is often necessary to apply the spray in a downward direction necessitating mounting of the gun with the front end lower than the back end. For these reasons ithas been necessary in the past to lubricate the gears of such guns with grease or other solid type lubricants. Use of such solid type lubricants has continued even though they have proven unsatisfactory for the relatively high speed gears required in these guns.

One. object of the invention comprises inter alia a heat fusible material spray gun of the wire feed type permitting the use of substantially fluid lubricants and providing adequate lubrication in other than horizontal positions of the gun.

A further object of the invention is such a gun construction utilizing as much as possible available parts of the gear train of such gun without requiring the addition of moving or wearing parts and without the necessity of increasing the size of the gun or appreciably increasing its wei ht.

A still further object of the invention comprises such a gun. construction including a. forced feed lubricating system.

These and still further objects of the invention will be seen from the following. description read in conjunctionwith the drawings in which:

Fig 1 representsa cross-sectional. side view, in the plane I-.-I of Fig. 2, of aspray gun. in accordance with the invention;

Fig. 2 is a partial cross-sectional view of the construction shown in Fig. 1: in the plane II -II thereof:

This may Fig. 3 illustrates a cross-sectional view of the gun housing (without spray head) shown in Fig. 2 in the plane Ila-Ila and shown in Fig. 4.- inthe plane IIIIII (showing the worm and portions of the countershaft intact);

Fig. 4 is a cross-sectional view of the construction shown in Fig. 3 in the plane IV-IV, thereof;

Fig. 5 is a perspective view of a gun housing showing the arrangement of certain parts of a spray gun construction in accordance with the invention.

The most common use of spray guns of the herein described type is that for the spraying of metal, In these guns a metal wire or rod is fed through and Sprayed from the gun. For convenience the following description is made in connectionv with metal spray gun constructions, it being understood. however, that the principle of the invention is applicable to constructions using other heat fusible materials, as for instance plastics.

Referring to Fig. 2, I. is a turbine rotor which is driven by jets of compressed air (not shown). Turbine rotor l is mounted on turbine worm shaft 2 which carries turbine worm 3. Turbine worm shaft 2 is. mounted to. rotate in ball bearing 4 and a second ball hearing at the opposite end. of the shaft (not shown). Turbine worm 3. engages countershaft worm, gear 5. The engagement of turbine worm 3 and countershaftworm gear 5 is also clearly shown in Fig. 3.

Referring to Fig. 3, worm gear 5 is mounted on countershaft B which rotates in ball bearings 1 and 8. Worm 9 is cut as an integral part of countershaft 6 and extends; from near theshoulder of counter-shaft 6 that engages bearing 8. for a; considerable distance,- toward worm gear 5. Worm; 9 engages worm wheel III (also clearly shown in, Fig. 4). Worm 9 is-longerthan necessary for operating engagement with worm gear [0. and extends further than its engagement length with worm gear Ill; in the directionof worm gear 5.

Referring to Fig. 4, worm gear lil is mounted on drive shaft. l I, which rotates in ball bearings l2. and I3. Drive shaft H. and countershaftz B are mounted for rotation in. main housing I14. Lowerknurl feed roll- I5: is mounted on drive shaft H by screwing ontothethreaded end thereof. Upper knurl. feed roll l6 is pressed onto totatable sleeve bearing H; which is mounted to rotate on axle l8. Lower spur gear I 9 is mounted on the threadedend of drive shaft H and: is driven thereby. Lower spur gear 19 engages upper spur gear 2 0 which is mounted on sleeve bearing H and fastened to upper knurl feed roll It by screws 2|.

In operation, the air driven turbine rotor I rotates turbine shaftv 2 which through worm 3 rotates worm gear 5, causing countershaft 6 and worm 9 to ,rotate. Worm 9 drives worm gear 10, rotatingdrive shaft H and lower knurl roll l and lower spur gear l9. Spur gear 19 engages upper spur gear 26 causing it and upper knurl roll IE to rotate.

Referring to Fig. l, the wire or rod 22 (which is to be sprayed) feeds through rear guide tube 23, between knurl rolls l5 and [6, through front guide tube 24, nozzle assembly 25 and to heating zone 26. Upper knurl roll axle I8 is mounted in hinged housing 21, said housing being hinged to gear housing M at 28. Hinged housing 21 is spring-pressed downward by spring 29, which is held in place and adjusted by thumb nut 3!]. Thumb nut 30 is attached to pressure spring screw 3|, which engages the thread of boss 32 which is rigidly mounted on housing I4.

In operation, thumb nut 30 is adjusted to spring press hinged housing 2! and upper knurl roll l6, down upon wire 22 thereby engaging said wire and forcing it into engagement with lower knurl roll. 15. As lower and upper knurl rolls are driven by the driving mechanism, they thereby feed wire 22 forward toward the heating zone 26.

In operation of the metal spray gun, combustible gas flows for instance into manifold grooves 43 (Fig. 1). Oxygen flows into manifold space 50.

Oxygen flows from manifold space 56 through jets 5| and into jets 52.' Combustible gas flows from manifold groove 43 together with the oxygen into jets 52. The combustible mixture of oxygen .andgas flows from jets 52 and through jets 53 to annular air space 65, and out through air cap 6 I,

whence it emerges as a conical stream surrounding the combustion zone 26.

A taperplug valve 66 is mounted ingas head 4| and controls or shuts off the flow of the combustible gas,,the oxygen and air by the turn of the valve handle.

Referring to Figs. 3 and 4, worm 9 is provided with a right hand thread. Turbine rotor l is provided with air jets (not shown) such as to cause its rotation to be clockwise as viewed from the turbine side of the metal spray gun. Worm 3 is also provided with a right hand thread.

In operation, therefore, right hand thread worm 9 rotates clockwise as viewed from the rear of housing I4.

'A section of the housing 14 is extended to form a longitudinal boss H surrounding the countershaft 6 and the worm 9. This boss extends to a position short of the front countershaft bearing 8, so as to provide an open space at its end 12. The other end of boss H extends to a position near the face of worm gear 5, providing between said boss and said gear face, space 13. Boss H is provided with a bore 14 which is slightly larger than, but relatively close to the size of the outside'diameter of worm 9. Bore 14 extends from the front end of boss ll rearward toward worm gear 5 to a position beyond the area of engagement between worm 6 and worm gear [6. Boss H is also provided with bore 15, which extends from the end of bore 14 to the end of boss H. Bore 15 extends sufficiently toward worm 9 to extend somewhat beyond the end of the thread of said worm. Bore i5 is sufificiently larger than the diameter of the section of countershaft 6 extending therethrough to provide annular space 16.

Boss H is provided with a large bore 11 at right angles to the bore 14 and of a size and position sufiicient to provide working clearance for the teeth of worm gear i6. Housing I4 and bottom plate [4a define lubricant chamber 1 la.

In operation, a sufficient amount of lubricant is added to gear housing [4 to reach to approximately the center line of countershaft 6 when said gear housing is in a horizontal position. Assuming that said gear housing is then mounted with the front end lower than the rear end at an angle, for instance, of approximately 30 degrees, then lubricant will be picked up through passage 12 by the action of worm 9 operating in bore 14, and by such action will be forced longitudinally through bore 14 'and'through passage 16, whence it will emerge through space 13. Centrifugal action caused by the rotation of worm gear 5 will cause the lubricant to flow outward across the face of worm gear 5 from space 13 and to be thrown outwardly from said worm gear face. This action not only provides lubricant directly to the threads of worm 3 but also causes sufficient spattering and fogging of the lubricant to additionally provide adeqate lubrication for ball bearings 4 and I.

A bayonet type lubricant gauge 18 (Fig. l) is preferably provided and mounted in housing l4 by threading into the housing at T9. Gauge 18 is provided with marks an to indicate the lubricant level required for adequate lubrication.

In operation, gauge 18 is removed and wiped clean over the marked area of the marks 80. The gauge is then replaced after the gear case is placed in a horizontal position and removed again, whereupon the operator can observe on the gauge the position of the lubricant level with respect to the marks 80.

In hitherto used constructions of spray guns of the herein described type the countershaft for geared driving connection between the rotor shaft of the gun and its wire feed mechanism drive shaft carries a relatively small worm of just sufficient length to engage the worm gear on the drive shaft for the wire feeding mechanism. In accordance with the invention, however, this worm is carried to extend to both sides of the effective worm gear engaging area and is provided with a tubular member in relatively close fit, thereby causing the countershaft itself to function as aforced lubricating feed. As is apparent, no addition of any moving or wearing element is necessary for obtaining this novel and beneficial result. The marks or gauge, may conveniently define the lubricating level within the gear housing and maybe then so selected that lubricant is suppliedto all moving or bearing parts within the, housing at other than horizontal positions of the gun.

The invention, as is apparent from the foregoing, thus essentially embraces in a heat fusible material spray gun of the wire feed type, having a gear train, including a countershaft for geared driving connection between the rotor shaft of. such. gunand its wire feed drive shaft, the improvement in lubricating means for such gun which comprises a worm at oneend of said countershaft for engagement with a worm gear on said feed drive shaft and extending to either side of the area of engagement with said worm gear, means defining a housing for said gear train, a substantially stationary tubular'member around said worm and defining with at least the major portion thereof a forced liquid lubricant feed between the end portions of said countershaft, an opening in said tubular member for worm gear engagement with said worm, said housing defining a fluid lubricant chamber in open communication with the intake end and the discharge end of said tubular member, thereby providing a circulating forced feed lubrication system in said gun.

Though the practical operation of the lubricating system in accordance with the invention is illustrated above in connection with a gun position pointing downward at an angle of approximately from the horizontal, it is apparent that this construction will provide adequate lubricant for all parts at greater angles and even where the spray gun points straight downward at an angle of 90 from the horizontal and even at still greater angles, in which case the gun would be at least partially upside down. In all these cases the lubricant filling the housing to a desired predetermined level, i. e., in the illustration shown, up to about the center of the countershaft (when in substantially horizontal position), will be either in contact with the feed end of worm 9 in boss H or will be in contact with some portion of the worm gear l0. In the latter case the lubricant is transported through opening 11 onto the feed worm 9 and thus brought to gear 5 even though gear 5 is not itself in direct contact with the lubricant.

Alternatively, when the gun is tilted in an upward direction within reasonably small angles, the predetermined oil level within the housing M will bring the oil into contact with the teeth of worm gear 5, thus effectively lubricating the same and causing transmission of the oil by splashing and fogging to all interconnected gears or worm parts. The predetermined lubricant level within housing 14 will also permit the sidewise positioning of the gun to either side; lubricant will then enter in either position at the feed end of worm 9 in boss II.

The substantially fluid lubricant that may be used in the structure in accordance with the invention may be any lubricant which is substantially capable of flowing at least under the operating conditions of the metal spray gun. It may include any substantially liquid lubricant, such r as oil, as well as greases and lubricants semisolid at ordinary temperatures and wherever in the specification and claims therefore the term fluid lubricant or similar expression is used, it is meant to designate thereby all such lubricants of the herein described character and nature.

The foregoing specific description is for purposes of illustration and not of limitation and it is therefore my intention that the invention be limited only by the appended claims or their equivalents wherein I have endeavored to claim broadly all inherent novelty.

I claim:

1. For use in a heat-fusible material spray gun of the wire feed type, the combination which comprises a wire feed gear train including a wire feed drive shaft worm gear, a countershaft, a driving gear at one end of said countershaft and a worm at the other end of said countershaft for engagement with said worm gear and extending to each side of the area of engagement with said worm gear, means defining a housing for said gear train, a substantially stationary tubular member around said worm, extending to adjacent said countershaft driving gear in spaced relation thereto and defining with at least the major portion of said worm a forced liquid lubricant feed between the end portions of said countershaft, an opening in said tubular memher for worm gear engagement with said. worm, said housing defining a fluid lubricant chamber in open communication with the intake end and the discharge end of said tubular member, thereby providing a circulating forced feed lubrication system in said gun.

2. The combination in accordance with claim 1 in which said opening in said tubular member is substantially confined to said engagement area.

3. For use in a heat-fusible material spray gun of the wire feed type, the combination which comprises a wire feed gear train including a wire feed drive shaft worm gear, a countershaft having a first wire feed driving end and a second driven end, and a worm at said first end of said countershaft for driving engagement with said worm gear and extending to each side of the area of engagement with said worm gear, gear means at the second end of said countershaft, said worm being threaded for teeth movement of said worm gear, within said area of engagement, in the direction of said second end, means defining a housing for said gear train, a substantially stationary tubular member around said countershaft including said worm, extending to adjacent said gear means in spaced relationship thereto and defining with at least a major portion of said worm a forced liquid lubricant feed between said first and said second ends, an opening in said tubular member for engagement of said worm gear with said worm, said housing defining a fluid lubricant chamber in open communication with the intake end and the discharge end of said tubular member, thereby providing a circulating forced feed lubrication system in said gun.

4. The combination in accordance with claim 3 in which said opening in said tubular member is substantially confined to said engagement area.

5. The combination in accordance with claim 3 in which said tubular member has a first sub stantially close fitting portion extending from adjacent said first end towards said second end beyond said area of engagement and defining with a major portion of said worm a forced liquid lubricant feed from said first to said second end, in which said tubular member has a second wider portion extending from said first portion towards said second end, and in which said worm extends into said second portion.

6. The combination in accordance with claim 5 in which said opening in said tubular member is substantially confined to said engagement area.

ARTHUR P. SHEPARD.

REFEREN6ES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,680,328 Eicher Aug. 14, 1928 1,811,058 Morgan June 23, 1931 1,850,340 Cowles Mar. 22, 1932 1,953,068 Barker Apr. 3,. 1934 2,183,485 Butzbach et a1 Dec. 12, 1939 2,268,202 Britten Dec. 30, 1941 

